/*
 * Copyright 2013-2015 www.snakerflow.com. Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in
 * compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law
 * or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND,
 * either express or implied. See the License for the specific language governing permissions and limitations under the License.
 */
package org.snaker.engine.helper;

import org.snaker.engine.SnakerException;

/**
 * 字符串处理帮助类
 * 
 * @author yuqs
 * @since 1.0
 */
public class StringHelper {
	/**
	 * 获取uuid类型的字符串
	 * 
	 * @return uuid字符串
	 */
	public static String getPrimaryKey() {
		return java.util.UUID.randomUUID().toString().replace("-", "");
	}

	/**
	 * 判断字符串是否为空
	 * 
	 * @param str 字符串
	 * @return 是否为空标识
	 */
	public static boolean isEmpty(String str) {
		return str == null || str.length() == 0;
	}

	/**
	 * 判断字符串是否为非空
	 * 
	 * @param str 字符串
	 * @return 是否为非空标识
	 */
	public static boolean isNotEmpty(String str) {
		return !isEmpty(str);
	}

	/**
	 * 根据字符串数组返回逗号分隔的字符串值
	 * 
	 * @param strArray 字符串数组
	 * @return 逗号分隔的字符串
	 */
	public static String getStringByArray(String... strArray) {
		if (strArray == null)
			return "";
		StringBuilder buffer = new StringBuilder(strArray.length * 10);
		for (String str : strArray) {
			buffer.append(str).append(",");
		}
		buffer.deleteCharAt(buffer.length() - 1);
		return buffer.toString();
	}

	/**
	 * 构造排序条件
	 * 
	 * @param order 排序方向
	 * @param orderby 排序字段
	 * @return 组装好的排序sql
	 */
	public static String buildPageOrder(String order, String orderby) {
		if (isEmpty(orderby) || isEmpty(order))
			return "";
		
		String[] orderByArray = orderby.split(",");
		String[] orderArray = order.split(",");
		
		if (orderArray.length != orderByArray.length)
			throw new SnakerException("分页多重排序参数中,排序字段与排序方向的个数不相等");
		
		StringBuilder orderStr = new StringBuilder(30);
		orderStr.append(" order by ");

		for (int i = 0; i < orderByArray.length; i++)
			orderStr.append(orderByArray[i]).append(" ").append(orderArray[i]).append(" ,");

		orderStr.deleteCharAt(orderStr.length() - 1);
		return orderStr.toString();
	}

	/**
	 * 简单字符串匹配方法，支持匹配类型为： *what *what* what*
	 * 
	 * @param pattern 匹配模式
	 * @param str 字符串
	 * @return 是否匹配
	 */
	public static boolean simpleMatch(String pattern, String str) {
		if (pattern == null || str == null)
			return false;

		int firstIndex = pattern.indexOf('*');

		if (firstIndex == -1)
			return pattern.equals(str);

		if (firstIndex == 0) {
			if (pattern.length() == 1)
				return true;

			int nextIndex = pattern.indexOf('*', firstIndex + 1);
			if (nextIndex == -1)
				return str.endsWith(pattern.substring(1));

			String part = pattern.substring(1, nextIndex);
			int partIndex = str.indexOf(part);

			while (partIndex != -1) {
				if (simpleMatch(pattern.substring(nextIndex), str.substring(partIndex + part.length())))
					return true;

				partIndex = str.indexOf(part, partIndex + 1);
			}

			return false;
		}
		
		return (str.length() >= firstIndex && pattern.substring(0, firstIndex).equals(str.substring(0, firstIndex)) && simpleMatch(pattern.substring(firstIndex), str.substring(firstIndex)));
	}
}
